A prior art T-driver is disclosed in U.S. Pat. No. 4,848,197 entitled "Multiple Bit Handtool" issued Jul. 18, 1989. U.S. Pat. No. 4,848,197 and its disclosures and drawings are incorporated herein by this reference.
A prior art ratcheting mechanism can be incorporated into the prior art T-driver of U.S. Pat. No. 4,848,197. This is known in the prior art. A prior art T-driver with a prior art ratcheting mechanism is shown in FIGS. 1, 2, 3 and 4 and is described below.
FIG. 1 shows a first elongated barrel 1 and a second elongated barrel 2. Barrel 2 is rotatably attached to barrel 1. Pin 3 provides the means by which the barrels are rotatably attached. Although barrels 1 and 2 are substantially cylindrical (i.e. substantially circular cross-section) this is not a requirement. The elongated barrels may have rectangular, triangular, oval or other-shaped cross-sections. Furthermore, the cross-sectional size and shape of a barrel may be different for different portions of the barrel.
Both ends of barrel 2 have bit holding means to receive and hold bits. One end of barrel 1 also has a bit holding means to receive and hold bits. The bit holding means of barrel 1 is in spindle 12 through an end hole at 13. Each of the bit holding means can be openings of barrel 2 and spindle 12 that are shaped and sized to receive and hold a bit. In this embodiment, the opening has a hexagonal cross-section and is adapted to accept and hold bits 4, 5 and 6. FIG. 1 depicts double-headed bits 4, 5 and 6. The main body of each bit has a hexagonal cross-section for a friction fit into the bit holding means. Resilient rings, magnets, springs, spring balls and the like can also be used to facilitate or enable a holding fit for bit-holding purposes. The T-driver is not limited to the bit-holding means described or shown as any means capable of accepting and holding a bit on the end of a barrel can be used. For example, the bit-holding means can be a threaded cylindrical portion onto which a threaded (single-headed) bit is screwed. The exposed heads or ends of the bits can be covered with protective caps (not shown).
Double-headed bits are preferred because they give the user of the handtool a greater number of available tool options without the need for carrying extra bits. A double-headed bit can be removed from the bit-holding means, reversed and inserted back into the bit-holding means to make a different bit head available for use. There is no preferred selection of bits (as such preference is a matter of choice by the user) but one useful selection of double-headed screwdriver bits is comprised of the numbers 1, 2 and 3 Phillips heads paired respectively with the number 6 slotted, number 4 slotted and number 10 slotted flat-heads. The bits useful in the T-driver are not limited to screwdriver head bits and can include any other kind of bit or tool (for example, socket wrench heads, Allen wrench, butterfly, torque, star and other bit tips).
A portion la (see FIG. 1) of barrel 1 is open, hollow and adapted to receive an end of barrel 2. Barrel 2 can be rotated (for example from a T-position as shown in FIG. 5) into (and nested in) the open area of portion 1 a to assume a "straight" position. A tight fit allows barrel 2 to hold whichever position (including an intermediate position) it is given by the user of the tool.
When the T-driver is in the perpendicular or T-position of FIG. 5, it is capable of producing a great deal more torque than a normal screwdriver or socket set. It also will provide more turning radius than a standard screwdriver or socket set. Considering its greater turning radius, it can apply the increased torque for a longer period of time in each rotation.
In use, the T-driver is functionally designed for barrel 2 to be placed across the palm of the hand with barrel 1 extending perpendicularly outwardly with two fingers on either side. An optional position has barrel 2 placed below the index finger. When high torque is not necessary, the T-driver can be used in the "straight" position and may be twisted with the fingers.
The dimensions of this T-driver can vary widely. The T-driver (bits excluded) in the depicted embodiment is about 5.75 inches long in the straight position. Barrel 1 is about 4.25 inches long and barrel 2 is about 2.25 inches long.
Incorporated into the prior art T-driver is a ratcheting mechanism having a rotatable wheel 10 with teeth 11. The rotatable wheel 10 is at the end of a spindle 12 (including shaft 91). The wheel 10, teeth 11 and spindle 12 are inserted into an open end of barrel 1 (i.e., the end that is opposite the end where barrel 2 is rotatably attached to barrel 1). The spindle 12 has an increased diameter (or head) at 13. The diameter of 13 is greater than the diameter of the opening into barrel 1 through which spindle 12 is inserted. After insertion of wheel 10, teeth 11 and spindle 12 into barrel 1, a key 14 is inserted into an opening (not shown) in barrel 1 to secure spindle 12 to barrel 1. Key 14 maintains a friction fit with the opening and prevents spindle 12 from sliding out of barrel 1.
The ratcheting mechanism further includes toggles 20 each with an arm 21 and a dimple 22. The toggles 20 (also shown as 20a and 20b) are positioned relative to each other in the manner shown in FIG. 2. The arms 21 form an opening for tooth 11a as shown in FIG. 2. Tooth 11a is one of teeth 11. A spring 24 is mounted on toggles 20. A switch is mounted on spring 24. The switch has a switch plate 27, a switch knob 28 for thumb or finger contact, and an extension 29 for insertion into hole 25 of spring 24. Extension 29 and hole 25 are sized and shaped such that hole 25 receives and accommodates extension 29. A sleeve 17 is positioned over barrel 1 and switch plate 27. Sleeve 17 has an opening 18 sized and shaped to accommodate switch knob 28 and to allow it to extent through sleeve 17 where it can be accessed by a human thumb or finger.
Pressure (e.g., by thumb or finger) on switch knob 28 causes switch plate 27, extension 29 and spring 24 to move in either direction along a path parallel to the length of elongated barrel 1, as shown by arrow 19 in FIG. 4. Switch 28 can be moved to any one of three positions. There is a tab 99 on each side of knob 28. Tabs 99 work with the shape of hole 18 in sleeve 17 to select the desired switch position. When the switch is moved to the first position, extension 29 pushes spring 24 into contact with dimple 22 of one of the toggles (e.g., toggle 20a). When moved to the second position, extension 29 pushes spring 24 into contact with dimple 22 of the other toggle (e.g., toggle 20b). When moved to the third position, the extension 29 and spring 24 are in an intermediate position between the first and second positions, and there is no significant contact with the dimple 22 of either toggle.
When switch 28 is in the third position, both arms 21 of toggles 20 engage one tooth (shown as 11a in FIG. 3) of teeth 11. The arms 21 engage tooth 11a on opposite sides of tooth 11a and prevent wheel 10 from rotating in either direction. Thus, bit 4 when inserted in spindle 12 can be turned by the T-driver in either direction to act on (e.g., turn) a screw or other device. There is no "give" in either rotational direction.
When switch 28 is moved to the first position, spring 24 makes contact with dimple 22 of toggle 20a and forces arm 21 of toggle 20a to lift and disengage from teeth 11 (e.g., from tooth 11a). With this arm disengaged, wheel 10 is free to rotate in one direction (i.e., the top of wheel 10 in FIG. 3 can rotate towards the disengaged arm) but not in the other direction. FIG. 4 shows this first position and shows contact area 23 of spring 24 contacting dimple 22 and causing arm 21 of toggle 20a to lift and disengage from teeth 11. In this position, bit 4 (when inserted in spindle 12) can be turned by the T-driver in only one rotational direction that acts on a screw or other device. This rotational direction is caused by the engaged arm 21 acting on tooth 11a and pushing it in a rotational direction towards the disengaged arm 21. There is "give" in the opposite rotational direction (i.e., the bit can't act on (e.g., turn) the screw or other device in the opposite rotational direction) because the disengaged arm 21 is not in position to engage and push tooth 11a. This allows the user of the T-driver through repeated back and forth operational motions of the hand and wrist to turn the screw (or other device) in one direction, with each return motion having no turning action or effect on the screw or other device, because the return motion is in the opposite rotational direction that "gives."
When switch 28 is moved to the second position, spring 24 ceases contact with dimple 22 of toggle 20a and then makes contact with dimple 22 of toggle 20b, which forces arm 21 of toggle 20b to lift and disengage from teeth 11 (e.g., from tooth 11a). With this arm disengaged, wheel 10 is free to rotate in the opposite direction (i.e., opposite to the direction of rotation when switch 28 is in the first position). In this position, bit 4 (when inserted in spindle 12) can be turned by the T-driver in only one rotational direction that acts on a screw or other device. This rotational direction is the opposite to that of the first switch position. Similar to the description above for the first position, but with the engagement of arms 21 reversed, the rotational direction that can act on (e.g., turn) a screw or other device is caused by the engaged arm 21 of toggle 20a to act on tooth 11a and push it in a rotational direction towards the disengaged arm 21 of toggle 20b. There is "give" in the opposite rotational direction (i.e., the bit can't act on (e.g., turn) the screw or other device in the opposite rotational direction) because the disengaged arm 21 is not in position to engage and push tooth 11a. In a similar manner to the first switch position, but in the opposite rotational direction, this allows the user of the T-driver through repeated back and forth operational motions of the hand and wrist to turn the screw (or other device) in one direction, with each return motion having no turning action or effect on the screw or other device, because the return motion is in the opposite rotational direction that "gives."